Liquid Crystal Display (LCD) does not emit light of its own and, in order to make the contents displayed on the LCD clearly seen, it needs the support of a backlight module to get the color. A side-type backlight module generally consists of necessary optical components such as light sources, a diaphragm, a reflector sheet, a light guide plate, and a rear panel.
The light sources of the side-type backlight module are arranged at the side of the light guide plate, and light emitted from the light sources directly enters the light guide plate, and travels from the side of the light guide plate to the other end, and when the light reaches a diffusion point, it is scattered at all angles and then exits through a light exit surface of the light guide plate. The main function of the light guide plate is to convert incident light into planar light, and then diffuse the light emitted from the light guide plate and deviate it from the direction, and finally gather the light in the normal direction of a display surface and adjust the divergence angle of the light through two light-condensing prism sheets whose surfaces are in the form of continuous zigzag grooves.
As to the side-type backlight module, light emitting diodes (LEDs) are usually used as the light sources. As the LEDs have a certain divergence angle, when the number of the LEDs is reduced, due to their loose arrangement, non-uniform brightness tends to appear at the light incoming side, i.e., a hot spot phenomenon, and due to non-uniform brightness at the light incoming side, the whole brightness of the backlight module will be non-uniform.
Besides, since the light sources of the current side-type backlight module are arranged at one side of the light guide plate, there exists the problem that the color gamut and transmittance of light are not high, thereby reducing the display effect.